Basic study of morphological changes and surface roughness of cavities prepared by TEA CO2 laser irradiation
Basic study of morphological changes and surface roughness of cavities prepared by TEA CO2 laser irradiation
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DOI：
10.1089/pho.2006.24.503
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发表时间：
2006-08-01
影响因子：
--
通讯作者：
Matsumoto, Koukichi
中科院分区：
文献类型：
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作者：
Nakamura, Yukio;Hossain, Mozammal;Matsumoto, Koukichi
目的：本研究的目的是研究横向激励大气压（TEA）CO2激光照射牙体硬组织的形态学变化和洞的表面粗糙度。背景资料：据报道，牙齿硬组织和骨可以通过长脉冲TEA CO2激光照射以最小的热损伤去除。然而，关于激光加工牙齿表面粗糙度的报道很少。研究方法：TEA CO2激光器在下列条件下照射离体人牙的牙釉质和牙本质表面：波长10.6 μ m;输出95 mJ/脉冲;脉冲重复率1 Hz;照射时间7.5 μ sec/次;能量密度7.9 J/cm（2）。通过组织学和扫描电子显微镜（SEM）检查进行形态学研究。制备的腔的表面粗糙度通过三维激光显微镜测量。结果：照射牙本质产生的缺损（705 +/- 11 μ m）比牙釉质（501 +/- 10 μ m）深。组织学观察显示激光照射后的牙本质边缘有一条嗜碱性线。扫描电镜观察发现釉质腔表面熔化，牙本质小管封闭。釉质腔壁和牙本质底的表面粗糙度分别为175 +/- 5 μ m和170 +/- 6 μ m。结论：TEA CO_2激光用于去除龋坏硬组织或洞腔预备是可行的。激光处理牙体硬组织有利于防龋，而窝洞表面粗糙度可提高修复材料的粘结强度。
Objective: The purpose of this study was to investigate the morphological change of dental hard tissue and surface roughness of cavities prepared by transversely excited, atmospheric pressure (TEA) CO2 laser irradiation. Background Data: It has been reported that dental hard tissues and bone can be removed by a long-pulse of TEA CO2 laser irradiation with minimal thermal damage. However, there are few reports on the surface roughness of lased teeth. Methods: The TEA CO2 laser was irradiated on the enamel and dentin surfaces of extracted human teeth under the following conditions: wavelength, 10.6 mu m; output, 95 mJ/pulse; pulse repetition rate, 1 Hz; irradiation time, 7.5 mu sec/shot; and energy density, 7.9 J/cm(2). Morphological studies were performed by histological and scanning electron microscopic (SEM) examination. Surface roughness of prepared cavities was measured by three-dimensional laser microscopy. Results: Irradiated dentin produced a deeper defect (705 +/- 11 mu m) than the enamel (501 +/- 10 mu m). Histological appearance showed a basophilic line at the margin of lased dentin. SEM observation noted that the surfaces of the enamel cavity seem to be melted, and dentinal tubules were sealed. The surface roughness of the enamel cavity wall and dentin floor were 175 +/- 5 mu m and 170 +/- 6 mu m, respectively. Conclusion: These findings suggest that it is possible to remove carious dental hard tissue or cavity preparation with the TEA CO2 laser irradiation. Lased dental hard tissue can facilitate caries prevention, and surface roughness of the cavities might improve the bond strength of restorative dental materials.